1. Field of the Invention
The present invention relates to a liquid crystal display device and a manufacturing method thereof.
2. Description of the Related Art
A liquid crystal alignment film to be used in a liquid crystal display device is formed through an alignment treatment, i.e., a step of imparting the liquid crystal alignment capability. As for the alignment treatment, the development of a photo-alignment treatment has been advanced recently. The photo-alignment treatment is a method of imparting the liquid crystal alignment capability to the surface of an organic film by irradiation of the surface of the organic film formed on a surface of a substrate with substantially linearly polarized light.
As a related art, JP 2007-226097 A discloses a manufacturing method of a liquid crystal display device using a liquid crystal display panel which enables high-definition display by preventing a decrease in the alignment control ability. More specifically, JP 2007-226097 A discloses a method of imparting alignment anisotropy to a film by irradiation of the film with polarized ultraviolet light while heating to 100° C. or higher in a photo-alignment treatment.
Further, JP 2003-255349 A discloses a method of forming a liquid crystal alignment film having alignment anisotropy by irradiation of a polyamic acid thin film with polarized ultraviolet light, followed by conversion of polyamic acid into a polyimide.